Residual strength model and cumulative damage characterization of asphalt mixture subjected to repeated loading

Abstract

Fatigue failure of asphalt mixture can be ascribed to the degradation of residual strength caused by fatigue loading. Describing the strength degradation helps to better understand the fatigue damage accumulation of asphalt mixture. This study aims at developing a residual strength model of asphalt mixture subjected to repeated loading and characterizing the cumulative damage. Firstly, a continuum damage mechanics (CDM) based damage evolution model was established. A phenomenological damage evolution model based on the differences between initial strength, residual strength and applied loading was then developed. Finally, the residual strength model was obtained by combing these two damage evolution models. Good agreement between the experimentally-obtained and model-predicted results indicated the reliability of the strength degradation model. The cumulative damage was investigated using the established damage evolution model.